1. Field of the Invention
The present invention relates to a novel coated pigment, and more particularly it relates to a coated novel pigment applicable to various products such as cosmetics and paints which is easily dispersed in water and is water-repellent when water in the mixture has been evaporated after dispersion, and cosmetic materials comprising said pigments.
2. Description of the Prior Art
Generally, various products containing pigments such as cosmetic and paint materials are roughly classified into aqueous non-aqueous, emulsion and powder types, and such products contain coated pigments which are selected according to the property of the medium used or the method of dispersing the pigment. Aqueous products, in particular, employ pigments coated with aqueous dispersant such as phosphoric acid, or pigments coated with silica in order to facilitate dispersion of pigments in the product. For practical purposes, however, aqueous products are also expected to exhibit the water-repellency after application. This is to prevent the applied product from being washed away from the surface by water or perspiration. Oil drops are often dispersed in an aqueous phase to obtain an emulsion so that the aqueous products may also be provided with water-repellent property. With aqueous products containing a large amount of said pigment coated with aqueous dispersant, addition of such oily drops will not give the products water-repellency or lipophilic property. In order to make aqueous products such as a cosmetic foundation containing a large amount of pigment lipophilic on the skin, it is necessary to make the pigment itself lipophilic. However, the present situation in the art is such that no pigments which are lipophilic in the aqueous system are available.
Aqueous cosmetics presently available on the market such as foundations, eye-liners, or eye-colors, give refreshment when applied on the skin. However, they are easily affected by perspiration, tear drops, water, sebum, etc., and since these products are not water-repellent, the make-up comes off easily and does not last. These products are further defective in that the make-up will become easily washed while swimming or in the rain because of lack of water-resistance. On the other hand, with non-aqueous phase especially oil-phase products, they feel soft and moist on the skin because the vehicle itself is oil. But the feel is also oily and sticky at the time of application. They also tend to "gather" because of sebum and the make-up is likely to come off. The demand, therefore, has been for a novel product which combines the advantages of aqueous and non-aqueous phases to overcome the respective defects mentioned above.
Conventional stick-type cosmetics, on the other hand, are generally made of so-called oil gels formed into sticks. They are either formed by extrusion using an oily substance such as oil, fat, wax, hydrocarbons, etc. as the binder or the structural component with an addition of a pulverulent body, or by casting fluid materials at a high temperature. Such oil gel stick cosmetics are typically and widely used in various products such as lipsticks, eye-shadows, eye-brow pencils, eye-liners, rouges, etc. These cosmetics come in various forms such as pencils or in a roll-up container, and are advantageous in that they can be directly applied to the skin, portable and handy in use and feel smooth on the skin. On the other hand, they are defective in that they are oily, come off easily, or give different feelings depending on the temperature at the time of use. All those merits and demerits of the conventional stick-type cosmetics arise from the limitations in mix ratio of powder, oily substance and wax. Since the ratio cannot be radically changed because of restrictions in manufacture and the quality requirements of the product, these merits and demerits have become inherent part of the essential properties of stick cosmetics. And yet, improvements on these points have been urgently felt. For example, the properties of cosmetics may differ depending on the ratio of powder to oily and wax such that when the base compound contains less than 50% of powder (oily range), it will give the feeling of oiliness; with more than 80% of powder (powdery range), it will give the feeling of powderiness; with 80 to 50% of powder (medium range) the base compound will give different feelings depending on the properties of individual component materials. Most of the conventional stick cosmetics are the oily type, because with a greater content of powder, operations such as kneading, filling and molding become more difficult. These conventional products generally contain from several to 40% of powder depending on the purpose, and thus inevitably entail the above demerits mentioned of oily cosmetics. Whereas if the powder content is greater, the tip of the stick where it directly touches the skin will become hardened as it wears by repeated use (caking), so much so that eventually it becomes unusable. This caking is a phenomenon of hardening of stick-type cosmetics caused by adhesion or permeation of sebum, perspiration and/or other cosmetics present on the skin into the cosmetic stick when the oil content is small (with cosmetics in the powdery or medium ranges).